Mohamed Ben Amor

Mitochondrial DNA haplogroup H structure in North Africa

BackgroundThe Strait of Gibraltar separating the Iberian Peninsula from North Africa is thought to be a stronger barrier to gene flow for male than for female lineages. However, the recent subdivision of the haplogroup H at mitochondrial DNA (mtDNA) level has revealed greater genetic differentiation among geographic regions than previously detected. The dissection of the mtDNA haplogroup H in North Africa, and its comparison with the Iberian Peninsula and Near-East profiles would help clarify the relative affinities among these regions.ResultsLike the Iberian Peninsula, the dominant mtDNA haplogroup H subgroups in North Africa are H1 (42%) and H3 (13%). The similarity between these regions is stronger in the North-West edge affecting mainly Moroccan Arabs, West Saharans and Mauritanians, and decreases eastwards probably due to gene flow from Near East as attested for the higher frequencies of H4, H5, H7, H8 and H11 subgroups. Moroccan Berbers show stronger affinities with Tunisian and Tunisian Berbers than with Moroccan Arabs. Coalescence ages for H1 (11 ± 2 ky) and H3 (11 ± 4 ky) in North Africa point to the possibility of a late Palaeolithic settlement for these lineages similar to those found for other mtDNA haplogroups. Total and partial mtDNA genomic sequencing unveiled stronger mtDNA differentiation among regions than previously found using HVSI mtDNA based analysis.ConclusionThe subdivision of the mtDNA haplogroup H in North Africa has confirmed that the genetic differentiation found among Western and Eastern populations is mainly due to geographical rather than cultural barriers. It also shows that the historical Arabian role on the region had more a cultural than a demic effect. Whole mtDNA sequencing of identical H haplotypes based on HVSI and RFLP information has unveiled additional mtDNA differences between North African and Iberian Peninsula lineages, pointing to an older mtDNA genetic flow between regions than previously thought. Based on this new information, it seems that the Strait of Gibraltar barrier affected both male and female gene flow in a similar fashion.

Alu polymorphisms in Jerba Island population (Tunisia): Comparative study in Arab and Berber groups

Jerba Island represents an interesting area because four distinct ethnic groups have been cohabiting there until now: Arabs, Berbers, dark-skinned people of sub-Saharan origin and Jews. Religious and cultural differences seem to have constituted an obstacle to their intermixing. Our aim is to provide further information on the genetic structure of the Arab and Berber groups for whom previous data based on haploid markers confirmed their reproductive isolation. Five polymorphic Alu markers (HS 4.69, Sb 19.3, TPA-25, ACE and APO-A1) were analysed in a sample of 43 Arabs and 48 Berbers of Jerba. The genetic relationships among these groups and several populations from North Africa, sub-Saharan Africa and Europe were analysed using genetic distances based on allele frequencies. The results showed a homogeneous distribution of Alu insertions in the two geographically close groups, reflecting ancient relationships between them. This study also revealed that Arabs from Jerba present close genetic distances to other North African populations, whilst Berbers of Jerba occupy an intermediate position among Mediterranean populations.

Genetic Diversity in Tunisia: A Study Based on the GM Polymorphism of Human Immunoglobulins

The GM polymorphism of human immunoglobulins is analyzed in three Berber populations of southern Tunisia and compared to other GM data. Genetic diversity among Tunisian populations is higher than that among Europeans but does not exhibit any significant geographic or linguistic structure. This result suggests a complex pattern of genetic differentiation.

Management of Foreign Bodies in the Aerodigestive Tract

Foreign body (FB) aspiration and ingestion are frequently encountered by emergent otolaryngology services. The authors describe their experience in the management of FB cases in the aerodigestive tract. We carry a retrospective study about 626 patients who came or were referred to our department between 1996 and 2007 with a history or suspicion of a FB in the aerodigestive tract (except nasal and oropharyngeal FB). All of them have undergone rigid endoscopy under general anaesthesia. Children younger than 10xa0years were the most involved (36.9%) followed by patients between 71 and 80xa0years old (11.3%). The FB were visible on clinical examination in 39 cases. Chest and neck X-ray, showed radio-opaque FB in 302 cases (48.7%). A total of 626 rigid endoscopies were performed. FB were encountered in 549 patients (87.7%). The most involved sites were the oesophagus (51.9%) followed by the tracheobronchial tree (33.9%) and the hypopharynx (13.5%). Bones (22%) and coins (20.1%) were the most frequently encountered FB. Successful removal was achieved in 521 cases (94.9% of the FB found). The complication rate after rigid endoscopy was 1.3%. FB in the aerodigestive tract are frequent and may lead to severe complications. Removal through the rigid endoscope still has its place as the most reliable method. Prevention and public education for this serious problem should be considered.

Molecular analysis in two Tunisian families with combined factor V and factor VIII deficiency

Summary.u2002 Combined factor V (FV) and factor VIII (FVIII) deficiency (F5F8D) is a rare autosomal recessive disorder caused by mutations in LMAN1 or MCFD2 genes which encode proteins that form a complex involved in the transport of FV and FVIII from the endoplasmic reticulum to Golgi apparatus. We report two novel mutations in MCFD2 gene and one recurrent mutation in LMAN1 gene that caused combined FV and FVIII deficiency in two unrelated Tunisian Muslim families. For the first family two patients were homozygous for a new missense mutation Asp81His in exon 3 of MCFD2 and heterozygous for a second new missense mutation Val100Asp in the same exon. Replacement respectively of the hydrophilic Asp residue with hydrophobic positively charged His and of the hydrophobic neutral Val residue with the Asp residue most likely disrupts the MCFD2–LMAN1 interaction, thus leading to the disease phenotype. For the second family a reported Arg202X mutation in exon 5 in the LMAN1 gene was identified in the homozygous state.

Small insertion (c.869insC) within F13A gene is dominant in Tunisian patients with inherited FXIII deficiency due to ancient founder effect

such as this. Some other causes of nerve compression in haemophilia should be considered in clinical evaluation, the most important is haemophilic arthropathy. The mechanism was well known and it started from repeated haemarthrosis, which caused synovitis then resulted in further inflammatory response, cartilage destruction, synovial fibrosis and epiphyseal over growth due to hyperaemia. Some surgical interventions can be considered for haemophilic arthropathy, such as joint debridement, alignment osteotomy, arthrodesis, total joint arthroplasty and nerve release. In our case, the X-ray of right elbow was consistent with haemophilic arthropathy, but the nerve compression symptom was not related to it. The case we report has some distinctive aspect for us to the following considerations: 1.This is the first reported case of a haemophilic patient with symptomatic ulnar nerve compression not caused by hematoma, intra-articular haemorrhage or joint contracture, but by lymphoid hyperplasia. 2. Musculoskeletal ultrasound has proved a valuable tool for detecting superficial mass in differentiate hematoma, cyst lesion or lymphoid hyperplasia.

Structural analysis of two novel mutations in MCFD2 gene causing combined coagulation factors V and VIII deficiency

Combined factor V and factor VIII deficiency (F5F8D) is a rare autosomal recessive bleeding disorder reported usually in the context of consanguinous marriage. F5F8D is characterized by mild-tomoderate bleeding and coordinate reduction in plasma FV and FVIII levels, as well as platelet FV level (OMIM 227300) [1]. The disease is caused by mutations in genes encoding lectin mannose binding protein (LMAN1) and multiple coagulation factor deficiency 2 (MCFD2), which are the components of the endoplasmic reticulum (ER)-Golgi intermediate compartment (ERGIC-53) involved in the FV and FVIII intracellular transport [1, 2]. LMAN1 is a type-I integral membrane protein that was first described as a 53-kDa marker of the ERGIC [3], whereas MCFD2 is a soluble luminal protein

Paradoxical reaction associated with cervical lymph node tuberculosis: predictive factors and therapeutic management

OBJECTIVESnThe aims of this study were to determine predictive factors of paradoxical reaction in patients with cervical lymph node tuberculosis (TB) and to discuss the therapeutic management of this condition.nnnMATERIALS AND METHODSnA retrospective study was performed of 501 patients managed for cervical lymph node TB over a period of 12 years (from January 2000 to December 2011). Statistical data were analyzed using IBM SPSS Statistics version 20.0.nnnRESULTSnParadoxical reaction occurred in 67 patients (13.4%), with a median delay to onset after starting TB treatment of 7 months. Lymph node size ≥3cm and associated extra-lymph node TB were independently associated with paradoxical reaction. Treatment consisted of surgical excision (71.6%), restarting quadruple therapy (10.4%), reintroduction of ethambutol (23.8%), and addition of ciprofloxacin (20.8%); steroids were given in two cases . All patients recovered after an average treatment duration of 14.91±7.03 months.nnnCONCLUSIONnThe occurrence of paradoxical reaction in cervical lymph node TB seems to be predicted by associated extra-lymph node TB and a swelling size ≥3cm. The treatment of paradoxical reaction remains unclear and more randomized trials are necessary to improve its management.

Paralysie faciale périphérique suite à une otite moyenne aiguë

OBJECTSnTo discuss clinical presentation and therapeutic approaches of facial paralysis in acute otitis media.nnnMETHODSnWe present five cases of facial palsy in children with acute otitis media managed in our ENT department during a period of 12 years (2001-2012).nnnRESULTSnThe mean age was 14.2 years; sex ratio was 0.66. All patients presented with a facial asymmetry, but only 3 of them had otalgia before the onset of facial asymmetry. The facial palsy delay was 3.3 days. The ear examination showed that the tympanic membrane was congestive in 4 patients, associated with a bulging in 2 patients, and a small perforation in one patient. Our patients presented grade III to IV initial facial palsy according to House and Brackmann staging. Computed tomography scan revealed a dehiscence of the bony facial canal in one patient. Antibiotic therapy associated with intravenous corticosteroids was administered in all patients. All patients underwent a facial kinesis therapy. A progressive improvement of facial palsy was observed in 4 patients and complete recovery of facial function in one case.nnnDISCUSSIONnConservative treatment associating intravenous antibiotic and corticosteroids with or without myringotomy is the standard approach.

Ectopic thyroid tissue: unusual differential diagnosis of cervical paraganglioma

Ectopic thyroid tissue (ETT) lateral to the midline is rare. Its occurrence in the carotid bifurcation is exceptional. We present a 45 years woman who consulted with a slow growing right cervical swelling. Clinical examination Ultrasonography, contrast enhanced CT and cervical MRI concluded to a paraganglioma. Intra-operatively, the tumor didn’t have the characteristic aspect of a paraganglioma. Complete excision was performed. Histology concluded to an ectopic micro-vesicular thyroid adenoma.Previous literature was reviewed to summarize clinical and radiologic characteristics of such rare entity. Despite its rarity, ETT must be included in the differential diagnosis of cervical paraganglioma.